Many devices and apparatuses have been developed to provide a selected degree of independence to people with various degrees of physical and mental disability, particularly during eating. Such devices and apparatuses have ranged from low-tech devices, for instance, those known commercially as the “Eatery” to robotic hi-tech systems, e.g., those sold under the names “Handy 1” and “My Spoon”. While useful, their specific design goals differ generally from one system or device to another. In some, an objective is to provide either a low-cost and easily manufactured device or one that is small, portable and easy-to-use device. In other cases, the focus has been more on modularity and adaptability to the user needs. Traditional systems and devices have also differed from one another in their user interface, control structure, mechanical form and artifacts, and the levels of user involvement in device (or system) operation.
Generally speaking, the self-feeding apparatuses both of the commercial type and research prototypes may be categorized into two groups: (i) body-controlled feeders (i.e., those controlled by a user's body part such as a mouth, a hand, or a foot), where the user controls directly all the steps of the eating process; and (ii) automatically controlled feeders, where the user activates a switch or some type of mechanism to initiate all or part of a pre-programmed eating cycle.
Automatic feeders are mechanically more complex, with simple to complex embedded electronics and control systems, and automate a part of, or all of, the process of selecting, getting a portion of food and offering it to the user. Usually, the feeders use a spoon utensil to scoop the food and some mechanism to transport the food-filled utensil to a predetermined position where the user can eat it. Often users must at least have the capacity to move body and/or head forward to take food off the spoon and must be cognitively able to differentiate between the switches. The advantage of these powered feeders is in their ability to allow users with more severe disability to operate them with minimum effort and with any residual movement available. The disadvantage is in their increased mechanical and electrical complexity, which results in a feeding device with greater safety risks to the user.
The most common automatic feeders are the Arm Feeders which often have 1 or 2 degree-of freedom mechanical arms with a tool attachment that can be lowered to a movable plate or bowl to scoop food and raised to a fixed position at the height of the user's mouth. Three commercial examples of Arm Feeders are the Winsford feeder, the Neater Eater feeder and the ADD (Assistance Dining Device) feeder. These feeders are equipped with arm mechanisms that are able to get food from one location only and as such it is required to provide for a degree of freedom (DOF) in the food container. Therefore, the typical Arm Feeder has a total of 3 DOF: 2 DOF in the arm and 1 DOF in the rotating or translating plate. For example, the 2 DOF arm of the ADD feeder rotates to scoop food from one of the three food bowls that have been rotated into position to allow the arm have access to the food and, later, translates to offer the food to the user. On the other hand, the arm of the Neater Eater feeder rotates downwardly under a 2 DOF cable drive mechanism to scoop food from a plate that has been rotated to access to food in a specific position on the plate and, later, rotates upwardly to offer the food.
Robotic Feeders can be categorized as more sophisticated Arm Feeders. They are designed with servo-controlled arms with higher degrees of freedom (3 to 6 DOF). Unlike the regular arm feeders, they do not require a moving food container since their increased DOF's permit them more flexible methods for retrieving the food from the plate. Two examples of alternate food retrieval methods can be seen in the 4 DOF, Handy 1 Robot, which scoops food with a flat-tipped spoon from one of seven compartments of a fixed plate, and the 5 DOF, My Spoon Robot, which grasps solid food with a spoon and fork hand mechanism from compartments in a Japanese lunch box. Also, as a result of higher DOF, some of these robotic systems are able to offer users the ability to perform other self-care activities of daily living (ADLs) in addition to feeding. Examples of these are the 6 DOF, DeVAR prototype system that permits users to shave and brush their teeth and the Handy 1 commercial system that permits users to make-up their face.
The MySpoon robotic feeding system (marketed by the Japanese company Secom Co. Ltd.) is the system that implements the more flexible arm mechanism in a small non-invasive package. It has implemented a novel mechanism for selecting particular pieces of food. On the other hand, the Neater Eater (of the English company Neater Solutions Ltd.) has the more flexible and modular system that allows it to serve a large variety of users. The fact that the system is modular means that it is easily reconfigurable (e.g. the arm can be separated from the base and the end-effectors can be replaced). The possibility of using regular plate and spoon makes it more familiar. Finally, the ADD (of the US company Meal Time Partners, corresponding to U.S. Pat. No. 5,282,711) has the best system for handling semi-liquid and liquid substances with minimum spills, a very flexible system for presenting food to the user and a very safe, force-feedback system governing the interaction of the device with the user.
Other types of automatic feeders are also known that do not have an arm configuration. For example, the devices according to U.S. Pat. Nos. 4,162,868 and 4,624,613 comprise mechanisms with one or two degrees of freedom with a spoon that translate to scoop and dispense food at a fixed position close to the user's mouth. Food is moved by another mechanism on the spoon. According to U.S. Pat. No. 4,162,868 a cam mechanism moves food in the spoon dispensing it to the user. According to U.S. Pat. No. 4,624,613 pressurized food is dispensed in a pneumatically moved spoon.
Despite their effectiveness the commercially available self-feeders for disabled people are still not being utilized in large numbers. As a matter of fact, these are still too expensive, too difficult to use, unreliable, inconvenient, difficult to transport, unattractive and too time-consuming in set up. It has been noticed that, even in those case wherein the operating effectiveness is higher, they are unable to meet the needs of users with minimum head and trunk control, i.e. with the most severe disability degree.